28 THE BUTTERFLIES OF NEW ENGLAND. 



would protect these parts of tlie head as effectually as the double cornution 

 of the Papilioninae. It is evident from the condition of the parts in the 

 Pierinae, as from the nearly or quite equal development of all the parts of 

 the eyes in all butterflies, that these projections are not for the purpose of 

 affording additional space for the material which is to form the parts beneath. 

 At the lateral base of the parts covering the future compound eye is a 

 strongly cur\ed, moderately broad and equal, smooth band, which I have 

 termed the ocellar ribbon (86 :22,23 ;87 :24) because it seems to be cor- 

 related with the curving row of ocelli of the larval head, the anterior curving 

 limits of which are generally marked in the larval head by a distinct 

 impression (86:24). At the upper posterior part of the head the antennae 

 take their rise, at some little distance apart, and at once diverge from each 

 other, passing in exactly opposite directions along the hinder part of the 

 head, between the front border of the prothorax on one side and the upper 

 termination of the ocellar ribbon on the other, cutting off a portion of the 

 latter, crossing to the thorax just below it and then continuing in a nearly 

 straight line posteriorly, between the wings and the legs, over a portion at 

 least of the abdomen. The front of the bulk of the head is limited below 

 by an angular suture, making a projecting angle, from which a piece (the 

 epistoma?) is sometimes cut off (87 :15). Just below it, variously developed 

 in form and size, but usually small, slender, longitudinal and pentagonal, 

 is a piece, probably the labrum, which separates on either side more or less 

 triangular opposing projections, broad at base, their apices joining or nearly 

 joining beneath the labrum ; these represent the mandibles. Behind these 

 (87 :G) is a long double ribbon, broad at base but narrowing for a short 

 distance, and then continuing nearly equal side by side in a straight line 

 posteriorly, beyond the hinder limits of the thorax ; they are the lateral 

 halves of the maxillae, the future spiral tongue; beneath their expanded 

 base, entirely concealed, with no separate sheath of their own, but lying 

 extended posteriorly and parallel to one another in a straight line over the 

 thorax are the labial palpi. 



The thorax. The thorax is distinctly divided above into its three usual 

 sections, the mesothorax being invariably largest and more or less tumid, 

 often provided with a greatly elevated central prominence and occasionally 

 with lateral ones of lesser size ; the prothorax, however, attains considera- 

 ble dimensions in the Lycaenidae, in which respect their chrysalids resemble 

 the larva rather than the imago ; in all the other groups both the pro- 

 thorax and metathorax are comparatively insignificant, the metathorax re- 

 sembling the first abdominal seg-ment : beneath and on the sides the thorax 

 is entirely hidden by its own appendages and those of the head ; the wings, 

 suboval in form and of course very much smaller than in the imago, are 

 spread over nearly the whole under surface and sides of the thorax and the 

 basal four segments of the abdomen, the hinder part almost entirely con- 



